Magnet-armature



(No Model.)

F. L. GREGORY. MAGNET ARMATURE.

No. 496,648. Patented May 2, 1893.

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B hi afijocne, iwgs s UNITED STATES PATENT FFICE;

FRED L. GREGORY, OF CHICAGO, ILLINOIS.

MAGN ET-ARMATU RE.

SPECIFICATION forming part of Letters Patent No. 496,648, dated May 2, 1893. Application filed November 16, 1892. Serial No. 452,161. (No model.)

To aZZ whom it may concern:

Be it known that I, FRED L. GREGORY, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Magnet-Armatures, of which the following is a specification.

This invention relates to improvements in the construction of magnets and armatures for actuating electric clocks, striking-mechanism, and like apparatus; the object being to provide a magnet and armature of relatively great power in proportion to the size thereof and the strength of the current used, and having a high'degree of uniformity in the power of the stroke throughout the several portions of the normal length of the same.

In the drawings accompanying and forming a part of this specification, Figure l is a plan View of a magnet-mechanism embodying my present invention. Fig.2 is a side elevation of the same; the frame work not being shown and the magnet-armature being shown at the end of its normal stroke. Fig. 3 isa side View similar to Fig. 2 but showing the armature in a different position.

Similar characters designate like parts in all the figures.

My improvement is especially adapted for use in connection with electric clocks, and is applicable to the self-winding clock described in Letters Patent of the United States N 0. 455,532, granted to me July '7, 1891.

The magnet shown in the drawings consists of the pair of cores, or poles, P and N, joined to the cross-bar 10 in any usual manner, and furnished with suitable coils, 8 and 9, respectively, for energizing said cores. The oscillating magnet-armature is supported adjacent to one end of the magnet, being carried by some suitable framework (not herein fully shown) adapted for holding both the magnet and the armature, as shown, for in stance, in my aforesaid patent.

According to my present improvements, the two similarly-shaped poles P and N of the magnet are oppositely disposed, and are preferably concave, as shown. The armature,

designated in a general way by M, is pivoted at a point 3 intermediate of its length and to said poles, and beyond the ends of these, so that the armature will swing close to the faces of the poles but free of them. The armature is in the form of a curved bar whose curvature is in the normal lines of magnetic force, and is pivotally supported on a line, a (0, Figs. 2 and 3, at one side of both of its end faces, 2 and 4, respectively. Intermediate to these faces the armature has a free space S between the ends 2 and 4 thereof. The armature M is shown carried by a shaft or spindle, 5, whose ends are shown in Fig. l journaled in some suitable bars or frame-plates, as F and F. Said spindle is also shown furnished with the arm 6 provided with the weight 7 for the purpose of retracting the armature from the position shown in Fig. 2 to that shown in Fig. 3. The action of the magnet when the cores or poles P and N are properly energized, is to draw the armature from the position shown in Fig. 3 to that shown in Fig. 2, this being its working stroke.

In practice,I find it preferable to make the curved armature-bar M of greater width at the ends than in the middle portion thereof, as will be understood from Figs. 2 and 3, the efficiency of the armature in proportion to its mass being increased by this mode of constructing the same. By having the open space, S, between the magnet and armature, this being otherwise shaped and supported in the manner set forth, the metal of the armature, at the beginning of its stroke as shown in Fig. 3, is located for the most effective action. The pole P draws upon the end 2 0f the armature, while the opposite pole N, draws upon the opposite end 4 of the armature, the attraction not being partially counteracted by any metal intervening between the ends of the armature. In practice, I have found that the improved curved form of armature herein shown, when of the same weight and stroke as one of the form shown in my aforesaid patent, has about twice the efficiency of such old form. This increase of power is of great utility and advantage in clocks and like apparatus, in the operation of which it is desirable to use a minimum amount of elec tricity so that the clock maybe operated for substantially concentric with its pivotal axis, IO

long periods of time with small batteries of and swinging in proximity to said poles, and

low t nslty. having its curvature following the normal flavlng thus described my invention, I line of the greatest magnetic force, substan- 5 cla1m- I tially as shown and described.

The combination With the magnet and its FRED L. GREGORY.

two poles, of the curved armature adapted to Witnesses:

be plvotally supported at a point beyond and J NO. HARMON,

between the poles, and having its pole-faces JOHN GRINNELL. 

